The quality of service (QoS) mechanism is a security mechanism of a network. A network device processes data with different priorities by using the QoS mechanism, to help reducing problems such as network latency and network congestion.
In a Long Term Evolution (LTE) system, a core network device maps different flows to evolved packet system (EPS) bearers. One EPS bearer includes one S1 bearer and one data radio bearer (DRB). The core network device communicates with a base station by using the S1 bearer, and the base station communicates with a terminal device by using the DRB. In a dual connectivity (DC) scenario, when a master base station determines to transfer a DRB to a secondary base station, the master base station needs to notify the core network device of an identifier of the DRB that is to be transferred to the secondary base station, so that the core network device may establish a transmission channel corresponding to the DRB with the secondary base station.
However, in a Fifth Generation (5G) communication system, higher requirements on QoS management of data is imposed. In other words, more refined QoS management needs to be performed on the data. In the existing technology, DRB-based information transmission performed between the master base station and the secondary base station cannot meet the requirements of the 5G communication system for QoS management.